The invention relates to a device for bending an intraocular lens with a flexible optical part, before the lens is implanted in the bent condition, by being passed through a small-sized incision (conventionally of 3 to 4 mm) provided in the eye (in general in the cornea).
Intraocular lenses with a flexible optical part have the advantage that they can be bent before they are introduced into the eye, which allows them to be passed into a small-sized incision. After it has been put into place in the eye, the optical part is opened out, and resumes its initial shape.
Intraocular lenses which can be bent have an optical part made of flexible material, which in particular can be selected from amongst the elastomers of polyurethane, the elastomers of silicon, and synthetic or organic gels (hydrogel, hydrated PMMA and/or HEMA, etc.).
Intraocular lenses additionally comprise a haptic part for securing to the inner wall of the eye, which can be formed from the same material as the optical part, or on the other hand can be formed from haptic loops made from another material, for example PMMA, added to the optical part.
Some intraocular lenses with a flexible optical part can be bent, at the choice of the surgeon, according to one or the other of several different bending lines, which are selected in particular according to the shape of the lens, its location or method for implantation, or the habits of the surgeon.
Thus, intraocular lenses comprising two curved haptic loops which are in the shape of a so-called xe2x80x9cCxe2x80x9d can be bent as a whole according to one or the other of two methods for bending.
According to the first method for bending, known as 6 o""clock-12 o""clock, the optical part is bent according to a diametral bending line, the extensions of which beyond the optical part intersect the free end part of each haptic loop.
When the lens has been bent, its two haptic loops extend longitudinally opposite one another, on the bent optical part. The implantation is then carried out in two steps. In a first step, the surgeon, who is holding grippers, between the jaws of which the bent optical part is gripped, introduces the first haptic loop, then the optical part, into the eye (into the capsule for a cataract operation), then opens the grippers in order to release the optical part. In a second step, the surgeon grips in the grippers the second haptic loop, which is still extending through the incision, and introduces it into the eye.
This first method for bending has the advantage that it is relatively easy to execute. However, it requires two implantation steps, and two passages of the grippers through the incision. The operation is thus relatively lengthy, and these repeated passages through the incision are a risk factor for the patient.
According to the second method for bending, which is known as 3 o""clock-9 o""clock, the optical part is bent along a diametral bending line, the extensions of which beyond the optical part do not intersect the haptic loops. When the lens has been bent, its two haptic loops overlap and intersect, on the same side of the bent optical part. The implantation can then be carried out in a single step, by introducing through the incision firstly the free ends of the two haptic loops, then, after rotation, the optical part.
According to this second method for bending, the operation of implantation is faster, but far more delicate, since the surgeon must control satisfactory passage and correct positioning of the lens in the incision, and opening out of the optical part, in the eye. In addition, it may happen that the haptic loops, which are presented in the incision with their free end facing forwards, collide with an ocular wall, which can give rise to lesions of the eye, or even breakage of a haptic loop.
Consequently, neither method for bending is preferable to the other, and in fact the inventors have found that, for the same intraocular lens, there are some surgeons who recommend and use the first method for bending, i.e. 6 o""clock-12 o""clock, and others who recommend and use the second method for bending, i.e. 3 o""clock-9 o""clock. In addition, it has been found that the method for bending selected can vary according to the personality of the surgeon, i.e. according to his tastes or habits, but also, for the same surgeon, according to the cases of surgical operations to be carried out, such that it is not possible to know in advance the method for bending which the surgeon will select for an operation.
U.S. Pat. No. 5,290,293 describes bending grippers in a single piece, which comprise receptacles to accommodate the implant, and a pair of bending support surfaces, which approach one another substantially in translation, according to a diametral direction of the lens, when manoeuvring handles are actuated, which are connected to one another by a flexible portion which forms a hinge. By means of this device, when the intraocular lens has been placed in the accommodation receptacles, it can be bent only according to a single bending line, perpendicular to the said diametral direction, only according to the 6 o""clock-12 o""clock bending method. In addition, the lens must firstly be handled in order to be put into place in the accommodation receptacles of the gripper, in order to be bent.
U.S. Pat. No. 5,139,501 describes a device for bending comprising a bending support surface which is secured onto a frame, and a bending support surface which is formed at the end of a slide, which is fitted such as to be mobile in translation relative to the frame, with studs for attachment of the haptic loops. This device permits bending only according to the 3 o""clock-9 o""clock method for bending. In addition, it should be noted that the slide is guided in translation towards the lens in a dovetail slide, such that any wear dust resulting from the friction of the parts during this displacement tends to be carried towards the lens, with the risk of dirtying the latter before the implantation takes place.
These devices for bending are only slightly successful commercially. In fact, when they are provided together with the lens (for example as packaging for the lens, which is placed in the device in the factory), the surgeon can use the lens only with the method for bending of the corresponding device for bending. It is therefore necessary either to plan to select the method for bending before the purchase is made, which is rarely possible, or to constitute stocks with each type of device for bending. In addition, if the device for bending is provided independently from the lens, risky handling is necessary in order to place the lens in the device for bending, which increases the time necessary for the operation, and the risks of dirtying and deterioration of the lens.
U.S. Pat. No. 5,281,227 describes a device for bending a flexible lens comprising a frame, a one-way bending unit comprising a pair of bending jaws supported by resilient flexible side members of this bending unit, which is fitted such as to rotate on the frame, and can be disconnected from the frame, and a cap. In order to bend the lens in place between the jaws of the bending unit, the cap is removed, then the bending unit is placed according to the required orientation, by being pivoted relative to the frame, the frame preventing the lens from pivoting on its support, then the bending unit is disconnected from the frame, the lens remaining in place between the jaws of the bending unit, then a gripper to grasp the lens is inserted between the jaws of the bending unit, and the two jaws are drawn close to one another by resilient deformation of the side members. This device has the disadvantage in particular that it requires sliding of the lens support of the bending unit relative to the lens, during pivoting for orientation of the bending unit, with the risk of damaging the condition of the surface of the optical part of the lens, which is particularly sensitive. In addition, bending of the lens requires a large number of handling operations, some of which are relatively delicate, by the surgeon. Furthermore, if there is any difficulty during the bending, there is a risk that the lens will fall on the floor, and be lost definitively. Moreover, the surgeon cannot leave the bending unit in an intermediate bending position, owing to the resilience of the side members. Also, the action of the surgeon on the side members is implemented directly, without any gearing down, on the bending jaws and on the lens, such that the bending cannot be carried out gradually and accurately. The quality of the bending is therefore closely associated with the skill of the surgeon.
The object of the invention is thus to eliminate these disadvantages, by providing a device for bending an intraocular lens, which, without prior handling of the lens relative to the device, makes it possible to bend the lens according to one or another of several methods for bending, corresponding to distinct diametral bending lines, at the choice of the surgeon, immediately before the operation of implantation.
The object of the invention is thus in particular to provide a device for bending which makes it possible to carry out bending of an intraocular lens with haptic loops in the shape of a xe2x80x9cCxe2x80x9d, at the choice of the surgeon, immediately before the operation of implantation, without prior handling of the lens relative to the device, i.e. according to a 6 o""clock-12 o""clock bending method, or according to a 3 o""clock-9 o""clock bending method.
The object of the invention is also to provide a device for bending of this type, which is simple and inexpensive.
More particularly, the object of the invention is to provide methods for production of a device for bending of this type, consisting of a minimal number of separate parts, and in particular at the most four parts which are mobile relative to one another.
The object of the invention is also, and more particularly, to provide methods for production of a device for bending of this type, which have limited risks of dirtying and deterioration of the lens during bending.
The object of the invention is also, and more particularly, to provide methods for production of a device for bending of this type, which are simple and immediately understandable, and which in particular make it possible to select the method for bending easily, quickly, and without risk of error.
The object of the invention is also, and more particularly, to provide methods for production of a device for bending of this type, which is quick and easy to handle, and by means of which the bending can be executed gradually, slowly and accurately, without requiring particular skill by the surgeon. For this purpose, the object of the invention is more particularly to provide methods for production of a device for bending of this type, in which the movement imparted by the surgeon on each mobile manoeuvring unit is geared down, the path of displacement of the corresponding mobile bending support surface being reduced relative to that of the mobile manoeuvring unit.
The object of the invention is also, and more particularly, to provide methods for production of a device for bending of this type, in which the device can act as packaging for the intraocular lens, and can be sterilised.
For this purpose, the invention relates to a device for bending an intraocular lens with a flexible optical part, be fore the lens is implanted, comprising:
means for reception of the lens;
at least one pair of bending support surfaces, which are designed to be able to be placed in contact with the optical part of the lens, in two areas of contact which are opposite according to a single diametral direction;
means for manoeuvring, which are connected to at least one bending support surface, and, when they are actuated, are designed to control displacement towards another bending support surface of a single pair of bending support surfaces, characterised in that the means for manoeuvring are designed such that, with a lens in place in the means for reception:
according to a first method for actuation of the means for manoeuvring, two bending support surfaces come into contact with the optical part of the lens, in two areas of contact which are opposite according to a first diametral direction, for bending according to a first bending line;
according to at least a second method for actuation of the means for manoeuvring, two bending support surfaces come into contact with the optical part of the lens, in two areas of contact which are opposite according to a second diametral direction, which is different from the first diametral direction, for bending according to a second bending line, which is distinct from the first bending line, such that the lens can be bent according to one or the other of the different bending lines.
Advantageously and according to the invention, in particular when the intraocular lens is of the type comprising two haptic loops in the shape of a xe2x80x9cCxe2x80x9d (throughout the text, this expression denotes curved haptic loops which are deformable flexurally, which are connected to the periphery of the optical part by one of their ends, and have another, free end, the two loops having a shape which is globally symmetrical relative to one another, in relation to the optical axis of the optical part), the first diametral direction and the second diametral direction forming between one another an angle of between 60xc2x0 and 120xc2x0, such that the lens can be bent according to one or the other of two bending lines which form between one another an angle of between 60xc2x0 and 120xc2x0.
In a variant, advantageously and according to the invention, the device for bending comprises:
a frame which includes the means for reception of the lens;
at least one pair of bending support surfaces, which are designed to be able to be placed radially in contact with the periphery of the optical part of the lens, in two diametrically opposite areas of contact, at least one of the two bending support surfaces, known as the mobile bending support surface of a pair of bending support surfaces, being fitted relative to the frame such that it can be drawn closer to the other bending support surface of this pair of bending support surfaces, and in that the means for manoeuvring comprise at least one mobile manoeuvring unit, which is connected to at least one mobile bending support surface, in order to control the displacements of the latter relative to the means for reception, when this mobile manoeuvring unit is actuated.
According to an advantageous characteristic of the invention, the device for bending is characterised in that it comprises:
a first pair of bending support surfaces, which are designed to be able to be placed in contact with the periphery of the optical part of the lens, in two opposite areas of contact, according to the first diametral direction, and, under the effect of the actuation of at least one mobile manoeuvring unit according to the first embodiment of actuation, to produce bending of the lens according to the first line of bending;
at least one second pair of bending support surfaces, distinct from the first pair of bending support surfaces, the bending support surfaces of this second pair being designed to be able to be placed in contact with the periphery of the optical part of the lens, in two opposite areas of contact, according to the second diametral direction, and, under the effect of the actuation of at least one mobile manoeuvring unit according to the second embodiment of actuation, to produce bending of the lens according to the second line of bending, which is distinct from the first line of bending.
In one embodiment, and according to the invention, the device for bending is characterised in that the means for manoeuvring comprise at least two mobile manoeuvring units, one of which is connected to at least one first mobile bending support surface of a first pair of bending support surfaces, and the other of which is connected to at least one second mobile bending support surface of a second pair of bending support surfaces.
According to another embodiment, advantageously and according to the invention, the device for bending is characterised in that the means for manoeuvring comprise a mobile manoeuvring unit, which is connected to at least one first mobile bending support surface of the first pair of bending support surfaces, and to at least one second mobile bending support surface of the second pair of bending support surfaces, this mobile manoeuvring unit being designed to be able to be actuated either according to the first method for actuation, or according to the second method for actuation.
Advantageously and according to the invention, the device for bending is characterised in that the mobile manoeuvring unit is fitted such as to rotate relative to the frame, in that the first method for actuation corresponds to displacement in rotation of the mobile manoeuvring unit in a first direction of rotation, and in that the second method for actuation corresponds to displacement in rotation of the mobile manoeuvring unit in the second direction of rotation, opposite to the first direction of rotation. As a variant or in association, the device for bending is characterised in that the mobile manoeuvring unit is fitted relative to the frame such that it can be displaced according to at least two distinct directions of translation, one of which corresponds to the first method for actuation, whereas the other corresponds to the second method for actuation. According to another variant, or in association, the device for bending is characterised in that the mobile manoeuvring unit is fitted relative to the frame such that it can be displaced according to at least one direction of translation, and according to at least two opposite directions according to this direction of translation, one of which corresponds to the first method for actuation, whereas the other corresponds to the second method for actuation.
It should be noted that there is nothing to prevent the mobile manoeuvring unit from being fitted such as to rotate and slide, i.e. with displacement components which are combined in rotation and in translation.
In addition, advantageously and according to the invention, the device for bending is characterised in that a first mobile bending support surface of the first pair of bending support surfaces and a second mobile bending support surface of the second pair of bending support surfaces are integral with a single intermediate mobile part, which is fitted and guided relative to the frame, and is connected to the mobile manoeuvring unit, such as to be able to be entrained in displacement under the effect of actuation of this mobile manoeuvring unit according to one or the other of the methods for actuation.
Also, in the different embodiments, advantageously and according to the invention, a mobile manoeuvring unit is connected to each mobile bending support surface of which it controls the displacements, by means of a cam and contact slide system. Thus, the movement of actuation by the practitioner on this mobile manoeuvring unit can have a path which is longer than that of the displacement of the mobile bending support surface.
In addition, in some embodiments, advantageously and according to the invention, each pair of bending support surfaces comprises a bending support surface which is fixed relative to the frame. Also, in some embodiments, advantageously and according to the invention, each mobile bending support surface is fitted relative to the frame such as to be able to be mobile at least substantially in translation, in particular according to a corresponding diametral direction.
In addition, advantageously and according to the invention, the device for bending is characterised in that the means for reception are designed to receive the intraocular lens, which is oriented, in particular relative to the frame, according to a single possible direction. In particular, and according to the invention, the means for reception advantageously comprise receptacles to accommodate the haptic part of the lens, and in particular haptic lenses in the shape of a xe2x80x9cCxe2x80x9d. The means for reception can be formed entirely or partially by the (fixed or mobile) bending support surfaces themselves.
It should be noted that since the lens is in place in the means for reception, according to its predetermined orientation, the surgeon does not need to handle the lens with grippers or the like, in order to select the method for bending. In fact, it is sufficient for him to actuate the means for manoeuvring of the device for bending, according to the method for actuation appropriate for the bending selected.
In addition, advantageously and according to the invention, the device for bending is characterised in that it constitutes packaging for an intraocular lens, and includes a cap which is closed onto the lens which is in place in the means for reception, this cap being designed to be able to be opened in order to permit access to the lens. Advantageously and according to the invention, this cap is designed also to serve the purpose of keeping the lens in place in the means for reception, perpendicularly to the plane of the optical part, i.e. according to the optical axis.
In addition, advantageously and according to the invention, the cap is designed such that, in the position in which it is closed onto the lens, it prevents any premature displacement of the means for manoeuvring, and, in its open position, it permits actuation of the means for manoeuvring according to one or the other of the methods for actuation.
The invention also extends to a device for bending, which is characterised in combination by some or all of the characteristics described previously or hereinafter.